rethink bundled archival binaries

[jesseditson]

Archival binaries are pretty big currently. This is an issue in archival-editor because the binaries are all downloaded - it's also an issue in archival-website because it makes the archival repos quite large.

We should move to a scheme where we just put the archival version in the manifest, and only fetch the binaries we need as some sort of setup script. This would also fix https://www.notion.so/jesseditson/Move-bin-archival-to-a-server-ebb60ef87d954a45a5ffbd7455106026?pvs=4

We could also then fallback to system archival - archival should already run archival compat before doing anything to a repo, so if your system is incompatible we can just tell you.